Recent research concerning the effects of sex hormones on growth hormone secretion in males indicates that the stimulatory effect of testosterone upon the somatotropic axis is predicated upon its ability to be aromatized to estradiol. (Weissberger, J. Clin. Endocrin., 76, 1993, 1407; Metzger, J. Clin. Endocrin., 76, 1993, 1147). For pre-pubertal, pubertal and adult males, it has been demonstrated that endogenous estrogens rather than androgens play a dominant role in regulating growth hormone secretions. (Caruso-Nicoletti, J. Clin. Endocrin. , 61, 1985, 896; Ho, J. Clin. Endocrin., 64, 1987, 51; see also references above) It has recently been reported that the antiestrogen tamoxifen blocks the estradiol induced surge in growth hormone secretion in both adult and adolescent males. (Weissberger, J. Clin. Endocrin., 76, 1993, 1407; Metzger, J. Clin. Endocrin., 79, 1994, 513).
Current treatments for disorders associated with an excess of growth hormone are primarily restricted to surgical removal of all or part of the pituitary or irradiation thereof. One alternative is treatment with bromocriptine mesylate, a dopaminergic agonist, but side effects such as nausea, vomiting, postural hypotension, "cardiovascular collapse", visual and auditory hallucinations, and cutaneous livedo reticularis are problematic.